The paper gives results of an evaluation of gas-chromatography/mass-spectrometry (GC/MS) and high-performance liquid chromatography (HPLC) methods for determining about 150 compounds from a list of potential principal organic hazardous constituents (POHCs), as defined in 40 C.F.R. Part 261, Appendix VIII. The methods evaluated are presented, analytical results are given, and the application of the evaluated methods to the determination of POHCs in incinerator effluents is discussed. These methods do not represent EPA's official method. (NOTE: As part of the Resource Conservation and Recovery Act (RCRA), the EPA has proposed regulations for owners and operators who treat hazardous waste by incineration. To ensure that these incinerators operate in an environmentally responsible manner, the regulations include a requirement that, for selected POHCs, a destruction and removal efficiency (DRE) of equal to or greater than 99.99% must be achieved (40 C.F.R. Part 264, Section 264.343). The evaluation of this paper is part of the supporting documentation for permit writers and for the incinerator-facility owners and operators.